Adjustable light fixture for u-shaped lamps

ABSTRACT

An adjustable light fixture for U-shaped fluorescent lamps accomodates lamps of different base spacing by providing spaced interconnected slots to receive moveable lamp sockets and moveable closure means to hide unused slots.

Nov. 28, 1972 R. c. PICCQLA 3,704,212

ADJUSTABLE LIGHT FIXTURE FOR USHAPED LAMPS Filed Oct. 22, 1970 22 FIG.2 FIG.3

4 INVENTOR. RICHARD PICCOLA ATTORNEY.

United States Patent 3,704,212 ADJUSTABLE LIGHT FIXTURE FOR U-SHAPED LAMPS Richard C. Piccola, Hawthorne, N.J., assignor to The Celotex Corporation, Tampa, Fla. Filed Oct. 22, 1970, Ser. No. 82,897 Int. Cl. H01r 33/08 US. Cl. 24051.12 Claims ABSTRACT OF THE DISCLOSURE An adjustable light fixture for U-shaped fluorescent lamps accommodates lamps of different base spacing by providing spaced interconnected slots to receive moveable lamp sockets and moveable closure means to hide unused slots.

BACKGROUND OF THE INVENTION 1) Field of the invention The invention finds use in the field of building construction and primarily in the installation of ceiling lighting fixtures or lampholders in suspended grid systems. Such fixtures are designed in modular units which fit into openings of preselected dimensions and are supported on interlocking grid members. The fluorescent lamps held in the fixtures of the invention are U-shaped rather than elongated lengthwise and have twin spaced bases.

Unfortunately, there is a lack of uniformity in the distance between the centerline of the bases of the U- shaped fixtures made by diflereut manufacturers. Rather than have separate fixtures adapted for use with the dif ferent lamps, it becomes desirable to have a fixture which can be changed in the field to fit lamps of different base spacing.

At the same time to secure fire-hazard ratings, it becomes necessary to provide some means to cover unused, exposed openings in the fixture.

In addition the speed and ease with which the lamp sockets can be changed to accommodate preselected lamps becomes a marketing consideration.

(2) Description of the prior art Some of the prior art fixtures have no provisions for altering the socket spacing, and thus the installer is restricted in the selection of lamps.

Other prior art fixtures include a sliding bracket which holds the socket and covers its own opening when going from one position to another. A still further prior art structure requires the complete disconnecting of at least one socket and its movement to a separate slot with subsequent reconnection to the electrical circuit.

The disadvantages of the prior art systems are overcome by the present invention which permits easy relocation of the sockets to accommodate lamps of dilferent distances between their bases.

It is, therefore, an object of the present invention to provide a novel lighting fixture which can easily be adapted to fit U-shaped fluorescent lamps with dilferent base spacings.

It is another object of the present invention to provide a novel lighting fixture which is safe and has a self contained moveable plate for covering an opening which would otherwise expose wiring.

SUMMARY OF THE INVENTION The present invention is directed toward an adjustable lampholder or lighting fixture for U-shaped fluorescent lamps which can have differently spaced bases. The lamp- "ice holder has moveable plates which cover otherwise exposed wiring showing through an uncovered slot.

Other features and objects of the present invention will become apparent to those skilled in the art when the present description is considered in the light of the accompanying drawing in which like elements are identified by like numerals and in which:

FIG. 1 is a general plan view of a suspended grid ceiling showing the lighting fixture of the invention with a glass lens removed;

FIGS. 2 and 3 show plan views of fluorescent lamps used with the invention;

FIG. 4 shows an end view of the light fixture of the invention taken along lines 4-4 of FIG. 1;

FIGS. 5 and 6 show an end view of the light fixture of the invention similar to FIG. 4 but with the moveable cover plate and the sockets being in stages of adjustment;

FIG. 7 is a rear view of a portion of the invention shown in FIG. 4, and

FIG. 8 is a cross-sectional view of a portion of the light fixture taken along lines 88 of FIG. 7.

Referring now to the drawing and particularly FIG. 1, thereof, there is shown a view of a ceiling looking upwardly from below. The ceiling comprises main suspension members 10 with cross-suspension members 11 connected to the main suspension members to form a series of open grids. The suspension members are generally inverted T-shaped in cross-section and are hung from an overhead support by wires or straps. The T-shaped configuration results in a pair of outwardly extending flanges in a horizontal plane with a central vertical web. In the illustrated version, this grid forms square openings into which acoustical panels 13 may be placed. Acoustical panels 13 rest along their outer peripheral areas on the horizontally extending flange portions of the grid members.

In one of the openings at light fixture 15 of the present invention may be supported. Light fixture 15 comprises a pair of fluorescent lamps 16 supported at their bases in sockets 20a, 20b, 20c and 20d respectively. A cover 22 overlies the lamps 16 and spans the grid opening. Cover 22 has outwardly and downwardly flairing edges 24 and 25 which are supported on the horizontal flanges of the suspension members 10.

FIG. 2 shows a typical U-shaped fluorescent ibulb 16 which has parallel sides 30 and 31 connected by a bight portion 33 to form a horse-shoe-shaped design. At the free ends of sides 30 and 31 are end caps 35a and 35b with outwardly extending connector pins adapted to be inserted into sockets 20a and 20b respectively. A strengthening rod 36 is connected between the end caps 35a and 35b.

The spacing between the center lines of end caps 35a and 35b of lamp 16 is designated as X. This distance may be preselected, as desired, but in current manufacture is generally 6 inches for one standard manufacturer. A similar typical U-shaped lamp 16a is illustratedin FIG. 3 for which the distance between end caps 37a and 37b is different from that of lamp 16. In the latter case, the conventional distance between end caps 37a and 37b for another manufacturer is 3% inches and is designated as Y. The problem is then to provide a lighting fixture which can be easily adjusted to fit either lamp, but in which there is no exposed wiring and which will pass a UL. Underwriters inspection.

Light fixture 15 has an end plate 40 which forms a vertical closure for one end of the fixture and which serves as a support for lamp sockets 20a, 20b, 20c and 20d respectively. The end plate 40 is arranged to hold a pair of lamps 16 or 16a and the pairs of sockets 20a, 20b and 20c, 20d receive the twin pins of end caps 35a and 35b. In FIG. 4, the spacing of the sockets 20a-20d is such as to accommodate lamps 16 with spacing X between the end caps 35a, 35b. FIG. shows an intermediate stage in the changing of location of the sockets while FIG. 6 shows the repositioned sockets 20a-20d to accommodate lamps 16a with spacing Y between its end caps 37a, 3711.

For convenience, only the adjustment of one set of sockets 20a and 20b will be discussed, with the understanding that the other pair of sockets 20c and 20d will be adjustable in the same manner. Under some conditions it may even be desirable to change only one set of sockets so each socket is independently moveable.

Sockets 20a and 20b are conventional porcelain sockets for fluorescent lamps and consist of a porcelain body 45 having a thickness of about /z inch, a rounded top 46 and a fiat bottom 47. Slots 48 and 49 are molded into the body 45 and spaced the standard distance between the pins of end caps 35a-37b. Mounted inside the body and accessible through the slots are metal connectors (now shown) which are crimped or otherwise secured to the ends of insulated wires 51 and 52. To shield the wire ends and their connections to the metal connectors from contact with the metal end of lamp fixture is a thin plastic shield 55. Shield 55 may be of rigid plastic such as polystyrene, polypropylene, or polyvinyl chloride polymer. Shield 55 is slightly larger than the porcelain body 45 so that the porcelain body 45 at no time contacts any metal of the lamp fixture 15. In addition, the sockets a-20d may be handled safetly because of the insulation efiect of the porcelain body 45 and the shield 55.

In addition, shield 55 has two integral fingers 60 and 61 extending outwardly behind the body 45. Fingers 60 and 61 are spaced a predetermined distance apart and have outwardly extending projections 62 and 63 to lock the shield, and thus the socket 20a, into firm engagement with one of the slots cut into the end plate 40 of light fixture 15. Fingers 60 and 61 are flexible enough to be moved toward each other to fit into slots, but are resilient enough to move back to their original positions to firmly engage the edges of slots in light fixture 15,. The spacing between the faces of projections 62 and 63 and the rear face of shield 55 is equal to the thickness of the metal of end plate 40. Thus when socket 20a is snapped into engagement with end plate 40 it is held in place by the engagement of projections 62 and 63 with end plate 40.

In the light fixture 15 there are four slots 68-71 cut into the metal end plate 40 to receive sockets 20a-20d, respectively. Since the slots are identical in configuration only slot 68 will be described, with the understanding that comparable comments apply to the other slots 69-71.

Slot 68 comprises two rectangular openings 80 and 81 connected by a narrow slot 85. The size of opening 80 is such that the distance between its edges 90 and 91 is equal to the spacing of fingers 60 and 61 of shield 55. The height of opening 80 is equal to the height of fingers 60 and 61. Slot 85 is much narrower than opening 80 so that there is an end of the slot 80 which will receive and lock with finger 61 to hold the socket 20a in position. Corresponding opening 81 of slot 68 has edges 92 and 93 to likewise receive fingers 60 and 61 when socket 20a is moved over to its alternate position (shown in FIGS. 6 and 7).

Socket 20a is completely removeable from opening 80 by compressing fingers 60 and 61 toward each other until projections 62 and 63 are inside of and clear of edges 90 and 91. Socket 20a may then be taken out of opening 80 by a forward pushing movement. Socket 20a may be inserted into opening 81 by pushing the socket into engagement therewith. Fingers 60 and 61 engage edges 92 and 93 of opening 81.

When socket 20a is moved from openings 80 and 81, some arrangement must be made to handle wires 51 and 52 and for this purpose narrow slot 85 is provided. When socket 20a is moved from openings 80 and 81, wires 51 and 52 are moved through slot 85 so that they are directly behind the sockets 20a at all times.

Obviously, sockets 20b-20d are moveable from the one opening of their respective slots 69-71 to another opening of slots 69 and 71 in a like manner.

To recapitulate, FIG. 4 shows sockets 20a and 20b engage in slots 68 and 69 respectively. Socket 20a engages the left-hand opening of slot 68, while socket 20b engages the right-hand opening of slot 69. In this manner, the maximum spacing between the sockets 20a and 20b is provided so that lamp 16 with spacing X between its end caps 35a and 35b can be accommodated.

FIG. 6 shows sockets 20a and 20b locked in the righthand opening 81 of slot 68 and left-hand opening 101 of slot 69 respectively to provide for the minimum spacing Y between the end caps 37a and 37b of lamp 16a.

Up to this point, the manner in which the various slots can be used to adjust the spacing between the socketsfor U-shaped lamps of different tube spacing has been fully described. Sockets 20c and 20d can be similarly placed in the openings in slots 70 and 71, respectively.

In order to cover the unused opening of each slot when the socket is held in one of the openings, a series of cover plates -113 are provided, one of said plates for each slot 68-71. Only one such cover plate 110 will be described in detail since the others can be identical and will function in a similar manner.

Cover plate 110 is centrally pivotally mounted with a rivet so that it can assume either of two terminal positions by a pivotal action. In one terminal position cover plate 110 covers opening 80 ofslot 68 and in its other terminal position it covers opening 81 of slot 68. A rotation of 90 will move cover plate 110 from one terminal position to another.

Cover plate 110 comprises a flat main portion 122 having a centrally located hole (not shown) through which a rivet 120 is inserted. Main portion 122 may be considered to be generally triangular in shape with a cut-out section 125 which is in the form of a right angular cut and conforms generally to the size of socket 20a so that when in its position shown in FIG. 4 it covers slot '81 but permits socket 20a to be seated in slot 80. Short flanges 127 and 128 are formed outwardly extending from main portion 122 to fit abutting the outer edge of shield 55. Along the long outer edge 129 of main portion 122 is an upstanding flange which makes the pivotal action of the plate 110 easier to accomplish because it presents a gripping member for ones fingers to hold while performing the pivotal movement of plate 110.

Plate 110 has such dimensions as to be pivotal within the confines of light fixture 15 and extend over the unused opening of slot 68. While a particular configuration is illustrated other configurations with the scope of the teachings will be apparent.

In summarizing the function of the present invention, there is provided a light fixture which can easily be adjusted to accommodate U-shaped fluorescent lamps with different base spacings. Spaced slots are provided so that moveable sockets can be easily spaced with respect to each other. The sockets are held in place by fingers integral with an insulating shield. A narrow slot interconnects the socket holding openings to permit the electrical wires to be moved from one slot opening to another without disconnecting the sockets from the wiring.

A rotatable cover plate is provided with a socket receiving opening. The cover plate is rotatable between two terminal positions so as to cover an unused opening of its respective slot.

I claim: a

1. An adjustable light fixture for U-shaped lampshaving different spacings between their bases comprising a light fixture cover;

at least one end plate connected to said cover;

at least one pair of spaced slots in said end plate, each slot being adapted to mount a lamp socket for receiving one of the lamp bases;

each of said slots having spaced rectangular openings and a narrower slot connecting said spaced openings of each slot;

a pair of pro-wired lamp sockets;

means connected to said sockets for releasably connecting said sockets individually in pre-selected ones of said openings; and

a pair of moveable cover plates pivotally mounted on said end plate,

each of said cover plates being of unitary construction having a central portion pivotally connected to said end plate and two slot covering portions symmetrically located about said central portion, each of said slot covering portions having at least one edge perpendicular to one edge of the other of said slot covering portions, forming a right angular cutout portion adapted to conform generally to the outer shape of one of said sockets, said pivoted connection being on a line perpendicular to and spaced from the center of said narrower slot,

each of said plates being adapted to move between two positions, in each of which positions a different rectangular opening is exposed to receive a corresponding one of said sockets.

2. An adjustable light fixture as recited in claim 1 in which the distance between two of said rectangular openings equals the spacing between the bases of one U-shaped lamp and the distance between another of two of said rectnagular openings equals the spacing between the bases of another U-shaped lamp.

3. An adjustable light fixture as recited in claim 1 in which the spacing between the two nearest openings equals the spacing between the bases of a U-shaped lamp and the spacing between the two most remote openings equals the spacing between the bases of a U-shaped lamp having a dilferent base spacing.

4. An adjustable light fixture as recited in claim 1 in which the rectangular openings are of preselected length and have edge walls and in which said releasable socket connecting means comprises a pair of rearwardly extending resilient fingers spaced a distance equal to the preselected length of said rectangular openings to engage said edge walls.

5. An adjustable light fixture as recited in claim -1 in which each of said cover plates has an outwardly extending flange to facilitate rotation.

References Cited UNITED STATES PATENTS 3,568,132 3/1971 Johnson 33950 R 2,559,151 7/1951 Getzoff 33936 3,562,511 2/1971 Reeves 24051.l2 R

SAMUEL S. MATTHEWS, Primary Examiner R. E. ADAMS, JR., Assistant Examiner US Cl. X.R. 339-50 R 

